Show Column Data In One Row

Question

Hello,
Tell Me how i can show a single column data in one row.
10
20
30
To
10,20,30

Answer 1

If you are OK with displaying comma separated list or column data you could:
SQL> select  ltrim(sys_connect_by_path(ename,','),',') ename_list
  2    from  (
  3           select  ename,
  4                   row_number() over(order by 1) rn,
  5                   count(*) over() cnt
  6             from  emp
  7          )
  8    where rn = cnt
  9    start with rn = 1
10    connect by rn = prior rn + 1
11  /
ENAME_LIST
SMITH,ALLEN,WARD,JONES,MARTIN,BLAKE,MILLER,SCOTT,KING,TURNER,ADAMS,JAMES,FORD,CLARK
SQL> To display as separate columns you would need to either know number of rows:
SQL> select  min(case rn when 1 then ename else null end) ename1,
  2          min(case rn when 2 then ename else null end) ename2,
  3          min(case rn when 3 then ename else null end) ename3,
  4          min(case rn when 4 then ename else null end) ename4,
  5          min(case rn when 5 then ename else null end) ename5,
  6          min(case rn when 6 then ename else null end) ename6,
  7          min(case rn when 7 then ename else null end) ename7,
  8          min(case rn when 8 then ename else null end) ename8,
  9          min(case rn when 9 then ename else null end) ename9,
10          min(case rn when 10 then ename else null end) ename10,
11          min(case rn when 11 then ename else null end) ename11,
12          min(case rn when 12 then ename else null end) ename12
13    from  (
14           select  ename,
15                   rownum rn
16             from  emp
17          )
18  /
ENAME1  ENAME2  ENAME3  ENAME4  ENAME5  ENAME6  ENAME7  ENAME8  ENAME9  ENAME10  ENAME11  ENAME12
SMITH   ALLEN   WARD    JONES   MARTIN  BLAKE   CLARK   SCOTT   KING    TURNER   ADAMS    JAMES
SQL> or use dynamic SQL.
SY.